This invention relates to: a process for preparing improved catalyst and sorbent supports; the supports prepared thereby; catalysts and sorbents comprising these supports; and to processes wherein such catalysts and sorbents are used.
Processes wherein solid contact materials, such as supported catalysts and/or supported sorbents are used, are, of course, well known in the prior art. These include petroleum processes such as catalytic cracking and hydrocracking, reforming and the like and various gas purification processes such as those involving the catalytic conversion of nitrogen oxides in the presence of ammonia or other reducing agent and those involving the adsorption of sulfur oxides.
As is also well known in the prior art, the activity of many, if not all, of these prior art catalysts and sorbents can be altered, and often improved, by an acid treatment of the carrier or support material either before or after the same has been shaped. Generally, however, such acid treatment has adversely affected the strength characteristics of the resulting catalyst or sorbent. This is particularly true with the so-called amorphous carriers such as alumina, silica, titania, zirconia, alumina-silica, silica-alumina and the like. As a result, acid treatment has not heretofore, been generally used in the preparation of catalysts and sorbents. It is, therefore, an object of the present invention to provide a process in which acid treatment could be used to increase the activity of catalysts and sorbents without adversely affecting their strength characteristics.